Could we step back a little and maybe revisit the premise that we need the gov't to be protecting children to begin with? That's what parents are supposed to be doing.
Let's actually create and maintain a society.
There are still places in the world where you and your family can literally fend for yourself against nature and rival gangs and so on if you're just super attached to the concept though, it's not like this option has been foreclosed.
But back to your original point, it's a pretty well-established function of government to protect the children within its borders from being harmed.
So which way it is - parents protect kids on their own or society/state helps somewhat?